This invention relates generally to gas turbine engines, more particularly to methods and apparatus for supplying feed air to turbine combustors.
Known turbine engines include a compressor for compressing air which is suitably mixed with a fuel and channeled to an annular combustor wherein the mixture is ignited for generating hot combustion gases. The gases are channeled to at least one turbine, which extracts energy from the combustion gases for powering the compressor, as well as for producing useful work, such as propelling a vehicle.
In at least some known turbine engines, compressor discharge air is preheated in a separate heat exchanger before being routed to the combustor via a duct. More specifically, the feed air is routed through to the combustor through a single feed point inlet. Although all of the air entering the inlet is channeled to the combustor, because the feed air may not be supplied uniformly to the annular combustor, unnecessary pressure losses and mal-distribution of supply air to the combustor. As a result, engine performance may be reduced and circumferential temperature gradients may be induced around the casing surrounding the combustor. Over time, such gradients may cause non-circumferential thermal growth which may adversely impact turbomachinery blade tip clearances and/or reduce engine performance. Furthermore, continued operation with such thermal gradients may reduce the useful life of the combustor.